Universal serial bus (USB) cables are increasingly used to deliver power to electronic devices in addition to their more traditional role of facilitating data communication. With the recent advent of the USB-C standard, USB cables can now deliver up to 100 Watts of power, thus facilitating high power applications that were previously unachievable via USB connection. However, it has been observed that the delivery of such high power can result in thermal damage to USB cables, especially in cases where the pins of a USB cable are dirty, bent, or otherwise predisposed to suboptimal connectivity.
One technique that has been employed for protecting against overcurrent/overheating in USB cables is the installation of a positive temperature coefficient (PTC) element in series with the power carrying conductors of a USB cable, wherein the PTC element has a resistance that increases as the temperature of the PTC element increases. Thus, as current passing through the PTC element increases above a predefined limit, the PTC element may heat up, causing the resistance of the PTC element to increase and drastically reduce or arrest the flow of current through the USB cable. Damage that would otherwise result from unmitigated fault currents flowing through the USB cable is thereby prevented.
While the above-described application of PTC elements in USB cables has provided a practical solution for protecting against overcurrents and overheating in earlier, lower-power (e.g., 5-20 watt) generations of USB cables, similar applications in modern, USB-C standard cables presents significant challenges. Particularly, a PTC element capable of handling 100 watts of power is prohibitively large and expensive for practical commercial application in a USB cable.
It is with respect to these and other considerations that the present improvements may be useful.